Based on the provided answer options, the correct answer that identifies a similarity between the U.S. economy in the early 1800s and the U.S. economy at the nation's founding is:
(B) The economy in the South was based on enslavement.
Both during the early 1800s and at the nation's founding, the Southern economy relied heavily on the institution of slavery, which played a significant role in shaping the economic system and labor practices in the region.